There is provided a film forming method including: adsorbing fluorine onto a substrate on which a region in which a nitride film is exposed and a region in which an oxide film is exposed are provided adjacent to each other by supplying a fluorine-containing gas to the substrate, and forming a stepped surface on a side surface of the oxide film by selectively etching the nitride film, among the nitride film and the oxide film, so as to cause a surface of the nitride film to be more deeply recessed than a surface of the oxide film; and after the adsorbing the fluorine onto the substrate and forming the stepped surface, selectively forming a semiconductor film on the nitride film, among the nitride film and the oxide film, by supplying a raw material gas including a semiconductor material to the substrate.
Legal claims defining the scope of protection, as filed with the USPTO.
2. The film forming method of claim 1, wherein the adsorbing the fluorine onto the substrate and forming the stepped surface is performed at a temperature lower than a temperature during the selectively forming the semiconductor film on the nitride film.
3. The film forming method of claim 1, wherein the fluorine-containing gas is a F2 gas or a HF gas used together with a NH3 gas.
4. The film forming method of claim 1, wherein the raw material gas includes at least one of Si and Ge.
5. The film forming method of claim 1, wherein the nitride film is a silicon nitride film, and the oxide film is a silicon oxide film.
6. The film forming method of claim 1, further comprising: before the adsorbing the fluorine onto the substrate and forming the stepped surface, removing a natural oxide film of the nitride film so as to expose the nitride film.
7. The film forming method of claim 6, wherein a NH3 gas and a HF gas are used to remove the natural oxide film.
8. The film forming method of claim 1, further comprising: after the selectively forming the semiconductor film on the nitride film, removing the semiconductor material formed on the oxide film by supplying a halogen-containing gas to the substrate.
9. The film forming method of claim 8, wherein the halogen-containing gas does not contain the fluorine.
10. The film forming method of claim 8, further comprising: repeating the selectively forming the semiconductor film on the nitride film and the removing the semiconductor material formed on the oxide film.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
September 25, 2020
January 17, 2023
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